Yes, the legality of such relicensing is questionable as that code was never developed outside of the kernel but as part of the kernel.

But i also disagree with it on a technical level: code duplication is _bad_. Why does the code have to be duplicated in user-space like that? I'd like Linux tracing code to be in the kernel repo. Why isnt this done properly, as part of the kernel project - to make sure it all stays in sync?

So for those two grounds i cannot give my permission for this relicensing, sorry.